The present invention is directed to an optical cable comprising a plurality of light waveguides that are each, respectively, combined in groups to form small bands, said small bands being assembled in stacks of bands which are respectively arranged in chambers of a core element that is formed by partitions, which chambers expand as a radial distance from the center axis of the core to the outside increases.
U.S. Pat. No. 4,983,013, whose disclosure is incorporated herein by reference thereto, and which corresponds to European Application A1 0 356 786, discloses an optical cable having a core element which is provided with approximately rectangular chambers. Such structures, which are also referred to as a chambered cables are frequently employed together with ribbon conductors or strip lines, wherein a plurality of light waveguides are combined to form a small band having approximately a rectangular cross section. A plurality of these small bands are united to form a stack of bands with a rectangular cross section, and the rectangular cross section of the stack is adapted to the approximate rectangularly fashioned chamber, which, likewise, has a rectangular shape. Only a small gap is left inside the chamber in order to guarantee a certain mobility of the stack of bands therein, however, a change in position, for example a twisting or tilting of the stack of the bands, should be prevented.
With an increasing plurality of small bands within a stack, the partitions between the individual chambers become broader and broader toward the outside and are lent in approximately wedge-shaped cross section. According to the above-mentioned U.S. Patent, the space presented here can be utilized to a certain extent in that additional depressions or grooves, which open toward the outside and have an approximately triangular cross section, are provided in the partition. These additional grooves are employed for other purposes, for example for the introduction of electrical conductors or the like. These cross sections of these additional grooves, however, are not suitable for the introduction of additional light waveguides, for example in the form of stacks of small bands, because, first, they are relatively small and, secondly, they have essentially a triangular shape.
U.S. Pat. No. 4,199,224, whose disclosure is incorporated herein by reference thereto, and which claims priority from German Patent Application 24 49 439, discloses a chambered cable, which is fashioned so that the chambers each have a radially expanding cross section and, thus, have approximately a sector-shaped structure. In this case, however, the light waveguides are introduced as discrete elements in these chambers and are not combined to form small bands or stacks.
Given an extremely high number of fibers, a structure having light waveguide bands leads to unnecessarily large cable diameters because the space in the region of the core element cannot be adequately utilized.